Mix sugar, water, corn syrup and salt together in a heavy saucepan.,______,Remove from heat.,Beat egg whites until they hold stiff peaks.,Pour 1/3 of syrup over egg whites, beating vigorously.,Continue cooking remaining syrup until it reaches 270° or the hard ball stage. Pour over egg white mixture, beating constantly.,Finish beating by hand until mixture is creamy and will hold its shape when dropped from a spoon (about 5 minutes).,Add nuts and flavoring. Drop from teaspoon on waxed paper or pour into a box lined with foil.,Cut into pieces if a box is used.,Store tightly covered.